For a pro audio application, could A2B be sent down a 2 conductor, shielded cable? ex. 1/4" guitar cable
I don't see any fundamental reason why it would not work. The main issue with ¼" instrument cables is that they usually have a high capacitance of ~30pF/ft. So, I suspect the length would be a limiting factor.
AES/EBU cables are designed for two-channel digital audio (SPDIF) and are probably a better choice in the pro audio market.